| Many people are surprised when they handle soft | | | | To understand how cloth can net a bullet consider a |
| body armor for the first time. In the first place it's | | | | hockey goal. The back of the goal is a net consisting |
| not really all that soft but more importantly it is | | | | of many lengths of interlaced cords fastened to the |
| relatively flexible and lightweight and, as such, seems | | | | goal's frame. When the puck flies into the back of |
| unlikely to be effective. How can cloth, which is | | | | the goal it contains a considerable amount of forward |
| essentially what this stuff is, stop anything, much less | | | | inertia or energy. The point where the puck strikes |
| a bullet? Even more mystifying to the equation is | | | | the net pushes back the furthest but at the same |
| that soft body armor cannot stop arrows or knives | | | | time the whole net reacts and also moves back as |
| but it does stop the most common types of bullets! | | | | the energy from the puck is quickly dispersed across |
| A Brief History | | | | the entire system of cords. In a very sort period of |
| It may be that many people become misled by the | | | | time the puck's energy is dispersed and it becomes |
| notion of armor. The marvelous metal masterpieces | | | | still. |
| worn by knights long ago stretched from head to | | | | Soft body armor works in much the same way. |
| toe making of the wearer an impenetrable tank. The | | | | Tightly woven fabric forms the basis of the net and |
| plate metal was designed to block everything that | | | | many nets are placed, one on top of the other, until |
| was thrown at it: arrows, swords, axes, rocks, etc. | | | | a dense system of layers all work together to |
| But these mighty metal suits became obsolete when | | | | absorb the bullet's energy. |
| gunpowder began flinging lead at the wearers. The | | | | Kevlar |
| plate metal was no match for the focused power of | | | | So the theory goes but cloth can only go so far. |
| a bullet. | | | | Soft body armor made as described above can |
| For a long time there was really no possible | | | | provide protection from the slow lead balls that were |
| protection against bullets. In a few cases, most | | | | common in the nineteenth century. But the twentieth |
| notably that of Ned Kelley in Australia, bullet-proof | | | | century saw cheaper and more widely available guns |
| metal armor was built. But it only enjoyed occasional | | | | that easily penetrated the armor. In the mid-1970's |
| success and it was always so heavy and restrictive | | | | the Dupont Corporation developed Kevlar, a synthetic |
| of movement that it was impractical. Then in 1881 Dr. | | | | material with an unusually high weight to strength |
| George Emery Goodfellow witnessed a gunfight | | | | ratio - five times stronger than the same weight of |
| wherein one man was struck in the chest. The bullet | | | | steel, in fact. Though originally designed for tire |
| was significantly slowed by a silk handkerchief that | | | | treads, the body armor uses of the new material |
| he had in his pocket. Another incident recorded by Dr. | | | | soon became apparent. When woven with fibers that |
| Goodfellow held that a man was saved by a | | | | were already in use Kevlar proved to be very |
| handkerchief bunched around his neck. This discovery | | | | effective for body armor applications. |
| led to the manufacture of silk based body armor. | | | | The material doesn't come without some |
| How It Works | | | | shortcomings. It looses effectiveness when wet |
| Soft body armor works in a completely different | | | | because water provides a lubricant for the bullet |
| way from plate metal armor. Rather than resist the | | | | allowing it to pass more easily through the fibers. |
| impact of the bullet as hard armor does, soft armor | | | | Kevlar also breaks down when exposed to ultraviolet |
| absorbs and spreads out the impact. The goal is not | | | | light which sunlight contains. But when shielded with a |
| to prevent the bullet's passage, although this is a | | | | waterproof and light proof layer Kevlar remains one |
| happy side-effect. The goal is to absorb the bullet's | | | | of the most common and trusted forms of soft |
| energy as harmlessly as possible. This is accomplished | | | | body armor. |
| by netting the projectile. | | | | |